The present invention relates to improvements in solids handling for effluent streams containing solids. The typical effluent stream for which the present invention is suitable is the discharge from a kitchen, particularly a restaurant kitchen. These discharges can Include a number of components including oils and greases, various food waste solids and, of course, water. These discharges from kitchens are not suitable to be sent directly to a sewage treatment plant, largely because of the presence of the oil/grease component. Sewage treatment plants do not handle these components well, and many local codes require their removal. This has traditionally been done in an in-ground grease trap. More recently, oil/grease separators have been available on the market to remove the oil/grease components. For example, the Lowe Engineering Company of Lincoln Park, N.J. makes products of this type, as shown in U.S. Pat. Nos. 4,051,024; 4,268,369 and 5,030,357. In addition, the assignee of the present application, Thermaco, Inc. of Asheboro, N.C. manufactures and sells oil/grease removal apparatus under the trademark BIG DIPPER. Exemplary of the patents owned by Thermaco are U.S. Pat. No. 4,235,726 to Shimko and U.S. Pat. No. 5,133,881 to Miller et al. The disclosure of these two patents is hereby incorporated by reference. What the various patents have in common is the presence of a surface which is hydrophobic and oleophilic, meaning that water does not wet the surface, but oil/grease does. The surface is passed through the upper surface of quiescent oil/grease and water in a holding tank. As the surface emerges, oil sticks to it, but water does not, so the oil can be scraped off and diverted to a separate storage container. The water is permitted to pass down stream through an exit in the lower part of the apparatus.
Typically, these devices have infeed units including a straining basket into which the solids are directed and trapped to remove them from the flow so they do not interfere with the oil/grease removal process. It is up to a restaurant employee to periodically open the unit and remove the strainer and dump its contents. The strainers are objectionable to handle because the solids may have strong odors. Also, the solids will have been immersed in the waste water, which will drip out of the basket. Thus, great care must be exercised to prevent the waste material from getting on the clothing of the person emptying the strainer basket.
Also, since this is an unpleasant chore, sometimes it's not done. If the strainer basket fills and is not emptied, the grease/oil separator unit ceases to be able to receive and transmit flows. The facility in which the device is installed will experience a failure, such as sinks not draining or upstream flows pooling in floor drains.
Finally, in larger units, the strainer baskets are so large that when they are relatively full, the weight of the basket of material to be dumped is great enough so as to injure the worker emptying the strainer.
Accordingly, there is a need in the art for an improvement in devices of this nature to eliminate the problems caused by the presence of strainer baskets.